Add path option(path2d) for hit regions on canvas2d.

Add path option(path2d) for hit regions on canvas2d.

The specification:
  http://www.whatwg.org/specs/web-apps/current-work/multipage/the-canvas-element.html#hitregionoptions

Intent to implement:
  https://groups.google.com/a/chromium.org/forum/#!topic/blink-dev/tRFguWa-oZc

BUG=328961
Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=177559

[zino, 2014-06-28 16:39:53]

Please take a look.

[Rik, 2014-06-29 03:22:22]

https://codereview.chromium.org/354333002/diff/1/LayoutTests/fast/canvas/canv...
File LayoutTests/fast/canvas/canvas-hit-regions-path2d-test.html (right):

https://codereview.chromium.org/354333002/diff/1/LayoutTests/fast/canvas/canv...
LayoutTests/fast/canvas/canvas-hit-regions-path2d-test.html:39:
context.fillStyle = "pink";
Try to add scaling to the context to make sure that it applies to the hit
region.

https://codereview.chromium.org/354333002/diff/1/Source/core/html/canvas/Canv...
File Source/core/html/canvas/CanvasRenderingContext2D.cpp (right):

https://codereview.chromium.org/354333002/diff/1/Source/core/html/canvas/Canv...
Source/core/html/canvas/CanvasRenderingContext2D.cpp:2383: specifiedPath =
m_path;
Will the current CTM be applied to the path that you pass in?

[zino, 2014-06-29 04:07:18]

Thank you for review.

FYI:
Currently, we can't get correct results because of context.isClipMode() bug.
So I've already uploaded a patch to resolve it.
https://codereview.chromium.org/352793006/

https://codereview.chromium.org/354333002/diff/1/LayoutTests/fast/canvas/canv...
File LayoutTests/fast/canvas/canvas-hit-regions-path2d-test.html (right):

https://codereview.chromium.org/354333002/diff/1/LayoutTests/fast/canvas/canv...
LayoutTests/fast/canvas/canvas-hit-regions-path2d-test.html:39:
context.fillStyle = "pink";
On 2014/06/29 03:22:22, Rik wrote:
> Try to add scaling to the context to make sure that it applies to the hit
> region.

I've already created the test for transform operation but I missed uploading.
I will update soon :)

https://codereview.chromium.org/354333002/diff/1/Source/core/html/canvas/Canv...
File Source/core/html/canvas/CanvasRenderingContext2D.cpp (right):

https://codereview.chromium.org/354333002/diff/1/Source/core/html/canvas/Canv...
Source/core/html/canvas/CanvasRenderingContext2D.cpp:2383: specifiedPath =
m_path;
On 2014/06/29 03:22:22, Rik wrote:
> Will the current CTM be applied to the path that you pass in?

Yes, you can see here.
2394     specifiedPath.transform(state().m_transform);

[zino, 2014-06-30 04:34:20]

I've just updated a test for path2d with transform operation.
Could you please review this?

Thank you.

[Rik, 2014-06-30 16:42:00]

lgtm

https://codereview.chromium.org/354333002/diff/20001/Source/core/html/canvas/...
File Source/core/html/canvas/CanvasRenderingContext2D.cpp (right):

https://codereview.chromium.org/354333002/diff/20001/Source/core/html/canvas/...
Source/core/html/canvas/CanvasRenderingContext2D.cpp:2390:
exceptionState.throwDOMException(NotSupportedError, "The specified path has no
pixels.");
I know this isn't part of this CL but we really shouldn't throw here.

[haraken, 2014-06-30 23:17:41]

LGTM for bindings/.

[c.shu, 2014-07-01 02:03:28]

https://codereview.chromium.org/354333002/diff/20001/Source/core/html/canvas/...
File Source/core/html/canvas/CanvasRenderingContext2D.cpp (right):

https://codereview.chromium.org/354333002/diff/20001/Source/core/html/canvas/...
Source/core/html/canvas/CanvasRenderingContext2D.cpp:2384: 
The above can be simplified as
Path specifiedPath = path2d ? path2d->path() : m_path;

[zino, 2014-07-01 05:37:29]

Thank you for review.

https://codereview.chromium.org/354333002/diff/20001/Source/core/html/canvas/...
File Source/core/html/canvas/CanvasRenderingContext2D.cpp (right):

https://codereview.chromium.org/354333002/diff/20001/Source/core/html/canvas/...
Source/core/html/canvas/CanvasRenderingContext2D.cpp:2384: 
On 2014/07/01 02:03:28, c.shu wrote:
> The above can be simplified as
> Path specifiedPath = path2d ? path2d->path() : m_path;

Done.

https://codereview.chromium.org/354333002/diff/20001/Source/core/html/canvas/...
Source/core/html/canvas/CanvasRenderingContext2D.cpp:2390:
exceptionState.throwDOMException(NotSupportedError, "The specified path has no
pixels.");
On 2014/06/30 16:42:00, Rik wrote:
> I know this isn't part of this CL but we really shouldn't throw here.

I'm not sure but,
According to the spec, if the specified path has no pixels,
throw a NotSupportedError exception and abort these steps.

[Rik, 2014-07-02 21:27:40]

On 2014/07/01 05:37:29, zino wrote:
> On 2014/06/30 16:42:00, Rik wrote:
> > I know this isn't part of this CL but we really shouldn't throw here.
> 
> I'm not sure but,
> According to the spec, if the specified path has no pixels,
> throw a NotSupportedError exception and abort these steps.

Ian agreed to change the spec so there's no longer an exception:
http://lists.w3.org/Archives/Public/public-whatwg-archive/2014Jul/0020.html

[zino, 2014-07-04 08:47:20]

On 2014/07/02 21:27:40, Rik wrote:
> On 2014/07/01 05:37:29, zino wrote:
> > On 2014/06/30 16:42:00, Rik wrote:
> > > I know this isn't part of this CL but we really shouldn't throw here.
> > 
> > I'm not sure but,
> > According to the spec, if the specified path has no pixels,
> > throw a NotSupportedError exception and abort these steps.
> 
> Ian agreed to change the spec so there's no longer an exception:
> http://lists.w3.org/Archives/Public/public-whatwg-archive/2014Jul/0020.html

Okay, I'll follow it up.
Thanks.

Justin, Could you please review this CL?

[Justin Novosad, 2014-07-04 15:02:45]

lgtm, with nit

https://codereview.chromium.org/354333002/diff/40001/Source/core/html/canvas/...
File Source/core/html/canvas/CanvasRenderingContext2D.cpp (right):

https://codereview.chromium.org/354333002/diff/40001/Source/core/html/canvas/...
Source/core/html/canvas/CanvasRenderingContext2D.cpp:2378: Path specifiedPath =
path2d ? path2d->path() : m_path;
specififiedPath is not necessarily a "specified path" since it can be m_path. 
Perhaps you should call it just "path" or "hitRegionPath".

[zino, 2014-07-05 03:01:22]

Thank you for review.

https://codereview.chromium.org/354333002/diff/40001/Source/core/html/canvas/...
File Source/core/html/canvas/CanvasRenderingContext2D.cpp (right):

https://codereview.chromium.org/354333002/diff/40001/Source/core/html/canvas/...
Source/core/html/canvas/CanvasRenderingContext2D.cpp:2378: Path specifiedPath =
path2d ? path2d->path() : m_path;
On 2014/07/04 15:02:44, junov wrote:
> specififiedPath is not necessarily a "specified path" since it can be m_path. 
> Perhaps you should call it just "path" or "hitRegionPath".

Done.

[zino, 2014-07-05 03:01:31]

The CQ bit was checked by jinho.bang@samsung.com

[commit-bot: I haz the power, 2014-07-05 03:02:06]

CQ is trying da patch. Follow status at
 https://chromium-status.appspot.com/cq/jinho.bang@samsung.com/354333002/60001

[commit-bot: I haz the power, 2014-07-05 04:08:11]

Change committed as 177559